US2214787A

US2214787A - Coating machine

Info

Publication number: US2214787A
Application number: US193698A
Authority: US
Inventors: Charles A Dickhaut; Lynn B Case
Original assignee: JOHN WALDRON CORP
Current assignee: JOHN WALDRON Corp
Priority date: 1938-03-03
Filing date: 1938-03-03
Publication date: 1940-09-17
Anticipated expiration: 1957-09-17

Description

p 17, 1940' c. A. DICKHAUT r AL COATING MACHINE riled larch 5, 193a "7 sheets-sheet 1 ATTORNEYS Sept 9 c. A. DICKHA UT ETA'L 2,214,737

COATING "ACHINE,

Filed lurch 3, 1938. "'7 'sh e'ets -shogtl '3 & g

INVENTCR 4 L4 0: 6 in;

ATTORNEYS c. A. DICKHAUT ET AL COATING IACHI'NE Iilod lax-en's, 193a 7 slioetssheet 4 INVENTORS 7? BY j ATTORN EY5 q 7 9 c. A. DICKHAUT ETAL 2,214,787 comma MACHINE I m larch 3, 193a 7 Sheets-Sheet s ATT'ORNEY5 COATING MACHINE Filed Inch 3, 1938 '7. Sheets-Sheet 6 I VENT S ATTORNEYS.

p 7, 1940. c.'A. DICKHAUT ET AL 2,214,787

COATING MA CHINE Filed larch 3, 1938 7 Sheets-Sheet 7 IHI ATTORNEYS Patented Sept. 17, 1940 COATING MACHINE Charles A; Dick haut and'Lynn B. Case, New Brunswick, N. J., assignors to John Waldron Corporation, New Brunswick, N. J., a corporation of New Jersey Application March 3, 1938, Serial No. 193,698

25 Claims.

This invention relates to coating machines and more particularly to a machine for coating I a web or strip of sheet material with a material which is solid at atmospheric temperature but softens or liquefies at elevated temperature, such material being exemplified by any resinous material which is normally solid but becomes fluid at elevated temperature, has no sharp melting point and is amorphous in solid state.

' An object of this invention is a machine which will rapidly and efliciently apply a smooth-surface uniform thickness coating of resinous or other similar material to a strip of sheet material such, for example, as paper, cardboard and the like.

According to the present invention, the coating material is liquefied or suiiiciently softened for application by heat and is applied to the strip of sheet material through the intermediary of one or more heated rolls having extremely smooth surfaces. The coating is then smoothed and chilled to solidify the applied material and produce a smooth coating. In the manufacture of the coating rolls, the cylindrical surfaces are machined to a high degree of accuracy while the rolls are heated uniformly throughout their length to approximately the expected temperature of the" 86 will be of greater depth along one longitudinalsection than along the remainder. For example, if the center of the coating roll is of higher temperature than the ends and as a consequence expands to a greater extent than the ends; the

4.0 central Iongitudinal section of coating on the strip of sheet material will difler'in depth from the side sections. Uniform spactng of the roll surfaces may be effected either byusing truly cylindrical rolls and uniformly heating each roll 45 throughout its length or by conforming the rolls so that their surfaces form true cylinders when brought to the elevated operating temperatur Preferably, the coating roll or rolls are equipped with suitable heating means and provision is 50 made for preventing escape of heat from the ends of the rolls so that the same are maintained at substantially uniform temperature throughout their length. Such escape of heat may be pre- .vented either by supplying heat to the supports for the rolls or by employing heat-insulating means between the ends of the rolls and the supports or bearings therefor. The coated surface v is smoothed preferably by means of a bar provided with a curved top surface terminating in an edge formed by a rear face inclined to the 5 tangent of said curved surface at slightly less than 90. The surface of the smoother is highly polished and has low specific adhesiveness 'for the coating composition and is of such hardness that it will not be scratched by the coating materials 10 For resinous coatings, a contact surface of chromium has been-found very satisfactory.

Other objects, novel features and advantages of this invention will become apparent from the following specification and accompanying draw- 15 ings, showing illustrative forms of apparatus embodying the invention and wherein:

Fig. 1 is a front elevation of a machine embodying the invention with an enclosing panel removed;

Fig. 2 is a vertical section taken on the line 2--2 of Fig. 3 with certain parts in the rear of the machine not shown .and with certain other parts shown diagrammatically; I

Fig. 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a section on the line ,4-4 of Fig. 2;

Fig. 5 is a front elevation of a modified form of apparatus; w v

Fig. 6 is a vertical section through the apparatus of Fig.5;

Fig. 7 is a section on the line 1-4 of Fig. 3;

Fig. 8 is a section on the line 8-8 of Fig. '7;

Fig. 9 is an enlarged section of the smoother bar shown in Fig. 8;

Fig. 10 is a view similar to Fig. 8 of a modificatlon; 1 g

Figs. 11 and 12 are fragmentary sectional views illustrating modifications in parts of the machine,

and

Fig. 13 is a fragmentary section arrangement of the temperature controller for the machine.

Referring to Figs. 1 to 4 inclusive, a base 10 supports a housing H which consists of two U-' shaped frames l 2, front and rear panels I3 and I4,

side panels I5 and I6, and a top panel 11 suitably interconnected (the front panel l3 being omitted from Fig. 1 for clarity sake). A bearing I8 is slidably mounted in the slot of each U-shaped frame I2 near the bottom of said slot and a sec- 0nd bearing I9 is slidably mounted in the slot of each U-shaped framemember I2 in the upper. portion of said slot, each frame member being provided with a stop 20 upon which the bearing l9 rests. A spring 2| is interposed between each 4'.-

illustrating 40 faces (Fig. 4). I rotation, but the section 28 is supported by the pair of bearings l8 and i9. A roll 22 is journalled in the bearings I8 and a roll 23 is journalled in the bearings IS, the surfaces of the rolls being spaced to an extent depending upon the thickness of coating to be applied. The shaft of the roll 22 is provided with a pinion 24 which meshes with a pinion 25 carried by the shaft of the roll 23. The

shaft of the roll 22 is provided with a sprocket 26 arranged exterior of the housing Each bearing I8 is supported by a post composed of an upper section 2! and a lower section 28 having complementary spiral contacting sur- The section 21 is fixed against worm wheel 29 journalled about a vertical axis in the bottom portion in the casing. H. A worm gear 30 suitably journalled in the casing meshes with the worm wheel 29 and is provided with a hand wheel 3|. Vertical adjustment of the bearings i8 is effected by operation of the hand 'wheels 3| withconsequent adjustment of the roll 22. I

A head 32 rests upon the top of each frame l2 and has a portion depending into the slot in said member. Studs 33 anchored to each frame member l2 extend through each head 32, and are provided with springs 34, the lower ends of which engage the head 32 and the upper ends of which en- 'gage nuts 35 on the studs. The springs 34 exert pressure on the heads 32 tending to oppose upward movement of the same and keep the bearings l9 engaged with the stops 20 but yielding to permit upward movement of the roll 23 away from the roll 22v to prevent damage to the rolls in the event of the passage therebetween of material of larger size than the spacing between the rolls. A shaft 36 (Fig. 4) is journalled in the heads 32 and is provided with a pair of eccentrics 31. An eccentric strap 38 surrounds each eccentric 31 and is connected to a bearing H) by a pin 39. The shaft 36 is-provided with an operating handle 40 and a sprocket 4|. 'Rotation of the shaft 36 is effective to lift the bearings l9 to move the roll 23 upwardly away from the roll 22.

A pan 42 (Fig. 4) is supported by the casing H in position to receive the roll 22, the ends of the panbeing slightly cut away to accommodate the shaft portion of the roll. This pan contains the coating material and suitable means (not shown) are provided for heating the contents of the -pan..

A doctor blade 22a is associated with the roll 22 tolimit the amount of coating material carried by the roll 22 out of the pan 42. A thin flexible doctor blade 230. extends across the surface of the roll 23 in position to engage a film of coating material on the roll-23. The blade is supported at one edge by a rod 23b from which the blade extends upwardly.

The shaft 36 carries depending arms 43 in the outer ends of which is journalled a small diameter roll 44. The roll 44 normally engages the strip of material to be coated to press it against the roll 23, but is moved out of contact therewith upon rotation of the shaft 36 to lift the roll 23.

A chain 45 (Figs. 3 and 4) extends from the sprocket 4| to a sprocket 46 mounted on a shaft 41 journalled in the frames 2. A doctor blade 48 is carried by the shaft 41 and'is swung into engagement with the roll 23 upon elevation of the latter, the rotation of the shaft 41 being effected termediary of the sprocket 4|, chains 45 and sprocket 46. 1

A ring 49 (Figs. 2 and 3) is rotatably mounted on a hub on each bearing l9 and is provided with upon rotation of the shaft 36 through the inan arm in which is journalled one end of the shaft of a roll 50. Each ring 49 is provided with a segmental gear 5| which meshes with a pinion 52 mounted on a shaft 53 journalled at eachend in a frame member l2. A hand wheel 54 isprovided for operating the shaft 53. Adjustment of the roll 50 is effected by rotation of the hand wheel 54. 1 h A hollow shaft 55 (Figs. '7 and 8) is journalled in the frames l2 and has its ends projecting through the casing At one end of the shaft is provided an adjusting handle 56 and at the other end is proviedd a clamp 51 having an eye through which the shaft extends. The arms of the clamp enclose the shaft 53 and a threaded member 56 is provided for tightening and releasing the clamp. This clamp arrangement locks the shaft 55 in any position of adjustment. A smoother bar 59 is set into a groove in the shaft 55 and is held in place by bolts 60. The shaft 55 and roll 50 are arranged at either side of the roll 23-above the center line of the roll. As shown in Figs. 8 and 9, the bar is provided with a curved top surface 59a. which terminates in an edge formed by the face 59b of the smoother bar which forms with the curved surface an angle X less than a right angle (Fig. 9). The curved surface hesion for the coating composition and is of sufficient hardness so that it will not be scratched by the coating material. For resinous coatings the surface 590. preferably is composed of chromium or other similar material having a minimum hardness in excess of Brinell, thereby reducing to a minimum the coefiicient of friction between; 'uch surface and the coating film which contact's' 't. The extent of the curved surface 59a and its curvature depends upon the viscosity of the coating, its thickness, the tension applied to the strip and the pressure to which the coating is to be subjected by the smoother.

- 59a is highly polished and has low specific ad- A pair of carriages 6| (Figs.- 1 and 2) are slidably mounted on the panel I6 and lead screws 62 are provided for effecting vertical adjustment of said carriages. A roll 63 is journalled in said 'carriages and an aperture is provided in.the

panelv l6 insubstantial alinement with the roll 63. panel l5 and in said heads are journalled rolls '65 and 66.

Rolls

61 and 68 are journalled in

brackets

69 and 10 supported by the top panel H; a roll II is journalled in thebase l0, and a roll l2I is journalled in brackets 13 attached to the base 0. v

V A shaft 14 is journalled in the base In and constitutes the main driving shaft of the machine. A chain 15 passes around a sprocket (not shown) on the shaft 14 and around the sprocket 26 to drive the roll 22. A chain 16 passes around a sprocket 11 on the shaft 14 and-around a sprocket 18 on the shaft of the roll 63.- Fixed A pair of heads 64 are supported by the and adjustable

idler rollers

19 and 86 are provided for engagement by the chain 16.

"The strip S of material to be coated passes from a supply roll shown at theleft of the machinein Fig. 1 under the roll over the roll 65,

through the panel l5, under the roll 50, between the

rolls

44 and 23, over the smoother 59, through the panel l6, under the roll 63, over the

rolls

66, 61. 66 and under the roll 12 to the roll-up mechanism shown at the right of the apparatus in Fig. 1. The roll 22 supplies liquefied coating material mmthe tank 42 to the roll 23 which in turn applies such coating material 0 the under surface of the strip S. The

rolls

2 and 23 are sprockets 81 so that the strip will lie between the roller 44 and the roll 23. The weight 85 takes up properly adjusted to apply the desired thickness 1 3 and 4), a heating unit 83 is provided in a groove in each surface of the central slot, such "heating units extending the full length of the slot. The

roll 63 is hollow (Fig. 2) and means 84 are provided for circulating. cooling liquid through the roll 63. The rolls and smoother are heated to the.

proper temperature by their respective heating elements 8| and 82, while the roll 63 is maintained atthe atmospheric temperature or below by the passage of cooling liquid therethrough. Also, .the frames l2, together with the bearings l8 and [8, are heated by the units 83 to the same temperature as the

rolls

22 and 23. By reason of the bearings being thus heated, there is completely eliminated all tendency for heat. to escape from the ends of the

rolls

22 and 23 so that these rolls are uniformly heated throughout their entire length, thus causing them to expand uni- Theposition of the roll 58 is adjusted'to deliver the' strip to the roll 23 at the proper angle of contact and the shaft 55 is adjusted to set the smoother 58 in the-proper position, depending upon the coating material used, the nature of the strip being coated and the thickness of the coating. When it is desired to interrupt the coating operation without stopping the

rolls

22 and 23,

the shaft 36 is operated by the handle 50 to lift the bearings, thus moving the roll 23 sufflciently distant fromthe roll 22 that the latter supplies no coating material to the former; At the same time, the doctor blade 48 is swung into-engagement with the'roll 23 to remove any coating material that may remain on the surface of the roll. Likewise, the roll 44 is moved out of contact with the strip S.

Sprockets 85 (Fig. 2) are rotatably mounted on the shaft of roll 63, sprockets 86 are rotatably mounted on the shaft 55, sprockets 81 are rotatably supported on the bearings l8, sprockets --of rods. A sprocket 86 is rotatably supported by each carriage 84. A chain 81 passes around the sprocket 85, over the

sprockets

86 and 81, under the sprocket 88, over the sprocket 88, under the sprocket 86, over

sprockets

80, 8|, 82 and back to the sprocket 85 and a cross bar 88 extends between the chains 81. The chains, together with the cross bar, constitute means for threading the strip S around the various rolls. The end of the strip S is attached to the bar 88 and the chains with the bar are moved through the path of the chains, drawing the strip through the path which it follows in passing through the machine. The threading operation is effected with the shaft 36 rotated to lift the roll 44 above the top of the any slack that may be produced in the chain by reason of changeof position of the sprockets 88 upon adjustment of the roll 58.

In the operation of this machine, the rolls 22.

and 23 together with the smoother bar 58 are heated to the I proper temperature. Inthe event that a resinous coating is to be applied, the rolls are heated to approximately 350 F. and the smoother bar is heated to a slightly highertemperature. Also, each frame is heated to the same temperature as the rolls. The resinous coating material is likewise heated to approximately 350 F. in the pan .2. With the roll 23 elevated and the roll 44 lifted, the strip S of paper or the like is threaded. through the machine and around'the cooling roll 63 and over the rolls on top of the machine to the take-up rolls. The furnisher roll 22 delivers a film of liquefied coating material, the thickness of which is de-,

termined by the spacing between the surfaces of

rolls

22 and 23 and is uniform through its entire width. The flexible doctor blade 23a levels out the ripples or unevenness produced in the film during its transfer from the furnisher roll 22 to the applicator roll 23. The applicator roll supplies the film to the strip S to which the film adheres. The film is compressed with a wedging action between the curved surface 58a of the bar 58 and the strip S. The highly polished surface 58a has a low'specific adhesion for the coating and is of sufficient hardness that it effectively resists scratching. The coated strip is drawn over the smoother bar 58 and the edge formed by the intersection of the curved surface 58a on the rear face 58b in such manner that the strip leaves the curved surface 59a at such angular relationship that the angle Y between the strip and the rear face 58b is less than 90. With such relationship existing between the coated strip and the rear face 58b, the filmof coating material is smoothed to produce a surface which is free from lines or other irregularities which would otherwise result due to tendency ;on the part of the coating material to adhere to the smoother. The coated strip then passes through the aperture in the panel I6 and around thecooling roll 63 from where it passes over the rolls 68,. 61 and 66 to the take-up roll.

I The roll 63 effects a material reduction in the temperature of the coated strip and return of the coated strip to normal temperature is effected by the circulation of cool air through the hood H enclosing the upper portion of the machine.

If heavy stock is to be coated, the roll 65 preferablyis provided with a heater so that the strip S is heated before entering the housing as otherwise an undesirable amount of heat is trans ferred from the coating film to the strip. The furnisher roll 22 and the applicator roll 23 may operate at the same surface speeds or the applicator roll may-operate at a higher surface speed than the furnisher roll. 7

The apparatus illustrated in Figs. 1 to 4 is designed for operation as a kiss coater while the apparatus illustrated in Figs. 5 and 6 is designed for'operation as a pressure coater. The structure of the pressure coater is similar in most respects to the kiss coater. However, the strip '8 instead of passing over the top of the roll 23 passes between the

rolls

22 and 23 and the roll 22 applies the coating material to the strip. The roll 58 of Figs. 1 to 4 and its supporting arrangement are omitted as are also the doctor blade 48 and the roll 44 and its supporting means. The shaft 55 with the smoother 59 is arranged at a lower position than in Figs. 1 to 4. The strip S otherwise follows the same path as previously 'j described. -The sprocket .15 is journalled on a shaft 15a supported by the casing II and a gear 99 fixed to the shaft 15a meshes with a gear I are omitted as in this form of the machine, the

-23 without. the use of chains.

fixed to the roll 22. The direction of rotation of the

rolls

22 and 23 is thus just the reverse of their rotation in Figs. 1 to 4. Also, the threading chains and their associated sprockets strip may be threaded between the rolls 22 and The .remaining features of the apparatus of Figs. 1 to 4 are included in the apparatus of Figs. 5 and 6.

As shown in Fig. 8, the shaft is provided with one ,or' more longitudinal grooves l0l in each of which is located a smoother bar 59. The

shoulderformed by the groove rigidly supports such smoother in proper position and the bolts hold it against the bottom of the groove. The various smoother bars may be of the same configuration so thata worn smoother may be substituted by a fresh smoother with minimum effort or each of the smoother bars may be of different configuration for use with different types of coating.

In Fig. 10, the smoother comprises a circular rod 590 seated in a channel in a holder 59d which in turn fits into the bearing groove MI. I

The surface of such channel is cut away as shown so that downward pressure on the rod 590 results in intimate contact of the edges of the channel with the surface 'of the rod to act as doctor blades. Means (not shown) maybe provided'for rotating the -rod either clockwise or counterclockwise in contact with the coating. For resinous coatings, the surface of the smoother rod is highly polished and has low specific adhesion for the jcoating material and is of sumcient hardness that it will not be scratched by the coating material. Preferably, for such coatings, the rod has a minimum'surface hardness in excess of Brinell and preferably the rod surface is composed of chromium.

Instead of providing heating elements in the frames I2, escape of heat from the ends of the

rolls

22 and 23 may be prevented in other ways.

As shown in Fig. 1 1, the bearings l0 and I! may,

be composed of heat-insulating material or material having very low heat conductivity. Also, as illustrated in Fig. 12, the bearings l8 and I9 may be composed of iron and be provided either' with bushings I02 of heat-insulating material surrounding the rollnecks or with heat-insulating liners I03 placed between the bearings and frames [2 or a combination of both.

The rolls are maintained at constant temperature through the action of one or more thermostats H4 arranged to receive heat therefrom as, for example, in the bearing I8 as shown in Fig. 13. The sensitive end of the thermostat may be located directly adjacent the shaft or neck of the roll and suitable electric connections (not shown) are provided so thatv the supply of electrical energy to the heaters in the respective elements is controlled to regulate their temperature and keep it uniform.

It is of course understood that various modifica-tions may be made in the structure of the devicewithout in any way departing from the spirit of the invention as defined in the appended claims. v r

We claim: 1. In a'machine for elevated temperature and solid at normal temperature to a continuously moving strip, a roll, means forsupplying heat to the interior of said roll, and means for heat-insulating the ends of applying material liquid at means for supplying heat to the interior of said roll, and bearings of heat-insulating material for said roll.

4. In a machine for applying material liquid at I elevatedtemperature and solidat normal temperature to a continuously moving strip, a roll, bearings for said roll, means for supplying heat to the interior of said roll, and heat-insulating members in said bearings for preventing loss of heat from said roll through said bearings.

5. In a machine for applying material liquid at elevated temperature and solid at normal temperature to a continuouslymoving web, a cylindrical roll having a cylindrical projection of reduced diameter at each end, means for supplying heat to the interior of said roll, means co-operating with said projections for rotatably supporting said roller,- and heat repellant means associated with'said projections for maintaining the surface of said roller at substantially uniform tem-' perature throughout its entire length.

- 6. In a machine for applying material liquid at elevated temperature and solid at normal temperature to a continuously moving web, a cylindrical roll having a cylindrical projection of reduced diameter at each end, means for supplying heat to the interior of said roll, means co-operating with said projections for rotatably-supporting .said roller, and means for supplying heat to said projections "for maintaining the surface of the roller at substantially uniform temperature throughout its entire length.

7., In a machine for applying material liquid at elevated temperature and solid at normal tem perature to a continuously moving strip, a pair of adjacent rolls, one of which applies hot liquefied I coating material to the strip, means for supplying heat to the interior of each roll, and means for heat-insulating the ends of said rolls.

8. In a machine for applying material liquid a elevated temperature and solid at normal temperature to a continuously moving strip, a pair of adjacent rolls, one of which contacts the strip to be coated, means for supplying heat to the interior of each roll, means for supplying hot liquefied coating material to one roll for application to said strip, and means exterior of said rolls for supplying heat to the ends of said rolls. 7

9. In a machine for applying material liquid at elevated temperature and solid at normal temperature to a continuously moving strip, a pair .of adjacent rolls, one of which applies hot liquefied coating material to the strip, meansfor supplying heat to the interior of each roll, and bearings of heat-insulating material for said rolls.

10. In a machine for coating a strip with coating material which 'liquefies at elevated temperature but is solid at normal temperature, apair of adjacent rolls, one of which applies hot liquefied coating material to the strip, means for supplying heat to the interior of eachroll, a heated smoother over which the coated strip passes with its coated surface contacting the smoother, and a housing enclosing said rolls and smoother.

11; In a machine for applying material liquid at elevated temperature and solid at normal temperature to a continuously moving strip, a frame, two pairs of bearings mounted on said frame, a roll joumalled in each pair of bearings, one of which rolls applies hot liquefied coating material to the strip, means for supplying heat to the interior of said rolls, and means for heat-insulating said rolls from said frames.

12. In a machine for applying material liquid at elevated temperature and solid at normal temperature to a continuously moving strip, a frame, two pairs of bearings mounted on said frame, a roll joumalled in each pair of bearings, one'of which rolls applies hot liquefied coating material to the strip, means for supplying heat to the interior of each roll, and means for supplying heat perature to a continuously moving strip, a frame,

two pairs of bearings mounted in said frame, a

roll joumalled in each pair of bearings, one of which rollsapplies hot liquefied coating material to the strip, means for supplying heat to the interior of each roll, and heat-insulating members between said frame and bearings for preventing loss of heat from said rolls through said bearings.

14. In a machine for coating a strip with coating material which liquefies at elevated temperature but is solid at normal temperature, a pair of adjacent rolls, one of which applies hot liquefied coating material to the strip, means for supplying heat to the interior of each roll, a heated smoother over which the coated strip passes with its coated surface contacting the smoother, a housing enclosing said rolls and smoother, and means for preventing loss of heat from the ends of said rolls.

15. In a machine for coating a strip with coating material which liquefies at elevated temperature but is solid at normal temperature, a pair of adjacent rolls, one of which applies hot liquefied coating material to the strip, means for supplying heat to the interior of each roll, a heated smoother over which the coated strip passes with its coated surface contacting the smoother, a housing enclosing said rolls and smoother, means for preventing loss of heat from the ends of said rolls, a roll exterior of said housing over which the coated strip passes with its coated surface contacting the roll, and means for circulating cooling liquid through said last-named roll.

16. In a machine for coating a strip with coating material which liquefies at elevated temperature but'is solid at normal temperature, a pair of superposed rolls, one of which applies hot liquefled coating material to the strip, means for supplying heat to the interior of each roll, a heated smoother over which the coated strip passes with its coated surfaces contacting the smoother, a housing enclosing said rolls and smoother, bearings for each roll, and means for supplying heat to said bearings.

17. In a machine for coating a strip with coating material which liquefies at elevated temperature but is solid at normal temperature, a. roll, bearings supporting said roll, means for supplying heat to the interior of said roll, a thermostat arranged with its sensitive portion in close juxtaposition to one of said bearings, and means responsive to said thermostat for controlling operation of said heating means.

18. In a machine for coating a strip with coating material which liquefies at elevated temperature but is solid at normal temperature, a roll, bearings supporting said roll, means for supplying heat to the interior of said roll, means to heat-insulate the ends of said roll, and thermostatic means for controlling the operation of said heating means to maintain uniform the temperature of the entire surface of said roll.

19. In a machine for coating a strip with coating material which liquefies at elevated temperature but is solid at normal temperature, a frame, two pairs of bearings mounted in said frame in adjacent relation, rollers joumalled in said bearings, means for supplying heat to the interior of said rolls, means for supplying heat-liquefied coating material to one roll and transferring the same in a film of uniform thickness to said second roll, means in said frame for supplying heat to said bearings, a heated smoother over which the coated strip passes with its coated surface contacting said smoother, a housing enclosing said rolls and smoother, a roll exterior of said housing over which the coated and smoothed strip passes, and means for circulating cooling liquid through said last-named roll.

20. In a coating machine, a frame, two pairs of bearings mounted in said frame, a roll journalled in each pair of bearings, means for simultaneously adjusting one pair of bearings, a doctor blade adapted to engage said one roll but normally arranged out of contact therewith, and means for swinging said blade into operative relation with said last-named roll upon adjustment of the latter.

21. In a coating machine, a frame having a vertical slot, two pairs of bearings mounted in said slot in superposed relation, a roll journalled in each pair of bearings, means for simultaneously lifting the upper pair of bearings, a roll normally arranged to engage a strip of material passing over the upper roll, and means for swinging said last-named roll out of such relation to the upper roll upon lifting of said upper roll.

22. In a machine for coating a strip with resinous coating material, a pair of spaced superposed rolls, the upper of which contacts the strip to be coated, means for applying hot liquefied resinous material to the lower roll for transfer to the upper roll, means for supplying heat to the interior of each roll, a thin flexible doctor blade associated with the upper roll to engage the film of resinous .material thereon, and a heated smoother bar over which the coated strip passes, said smoother bar having a curved contact surface and a rear face forming less than a right angle with said curved surface.

23. In a machine for coating a strip with resinous coating material, a pair of spaced superposed rolls, the upper of which contacts the strip to be coated, means for applying hot liquefied resinous material to the lower roll for transfer to the upper roll, means for supplying heat to the interior of each roll, a thin flexible doctor blade associated with the upper roll to engage the film of resinous material thereon, and a heated smoother bar over which the coated strip passes, said smoother bar having a curved contact surface and a rear face forming less than a right angle with said curved surface.

24. In a machine for coating a strip with coat-- ing material which liquefies at elevated temperature but is solid at normal temperature, heated means for applying the coating material to the strip and heated smoother means over which the coated strip passes, said smoother means comprising a bar consisting of a base member and a head having a curved contact surface terminating in a sharp edge formed by a rear face defining less than a right angle with said curved surface, a

support for said bar having a channel in which said base member is received, and means 'for detachably retaining said. base member in said channel.

25. In a machine for coating a strip with coating material which liquefies at elevated temperamm but is solid at normal temperature, heated means for applying the coating material to the strip and heated smoother means over which the coated strip passes, said smoother means comprising a bar consisting of a base member and a headhaving a curved contact surface of low specific adhesion for the coating material and minimum hardness of 150 Brinell, a support for said I bar having a channel in which said base member is received, and means for detachably retaining 10 said base member in said channel.

CHARLES A. DICKHAUT. LYNN B. ,QASE. I